PROJECT SUMMARY/ABSTRACT The apparent and impactful role played by parents’ intrusive-controlling (IC) parenting behaviors in the stability of children’s behavioral inhibition (BI) and as a moderator of risk for anxiety disorders (AD) has motivated treatment and prevention approaches that specifically target these behaviors. Parents who are easily aroused and have difficulty regulating in response to their child’s distress are prone to ineffective, harsh, and intrusive parenting, and a growing body of research demonstrates that parents’ physiology influences their behaviors, particularly during times of heightened stress. However, very little research has investigated the influences of parents’ neurophysiological reactivity and regulation on IC behaviors. Moreover, although there is growing evi- dence that neurophysiological functioning may predict behavior change in response to intervention, no re- search has examined this possibility with regard to IC parenting or children’s BI. The current proposal leverag- es an existing randomized controlled trial dataset (n = 151 parent-child dyads) to (Aim 1) establish the influ- ences of parents’ neurophysiological regulation on their IC parenting behaviors and whether these links are moderated by parents’ anxiety and (Aim 2) test the influences of parents’ neurophysiological regulation and IC parenting on reductions in child BI across treatment, whether children’s neurophysiological regulation mediates these associations, and the moderating role of parents’ anxiety. The Turtle Program (TP), a multi-component (i.e., combination of Parent-Child Interaction Therapy and children’s Social Skills Training) early intervention program, was developed to target IC parenting to reduce risk for anxiety among preschool-aged children by comparing it to the best available psychoeducational treatment for BI, Cool Little Kids (R01MH103253; PIs: Rubin and Chronis-Tuscano).The current proposal specifically examines parents’ sympathetic nervous system (SNS) and parents’ and children’s parasympathetic nervous system (PNS) functioning assessed across social stressors, an impactful next step given PNS and SNS functioning index neural structures implicated in arousal and attention regulation (RDoC Arousal and Cognitive Systems) and may inform treatment response. TP and CLK, which have both demonstrated reductions in IC parenting, systematically vary in intensity, structure, and required resources. As such, the current proposal will provide preliminary evidence for who might need more intensive treatments which will promote the development of personalized intervention and reduce patient bur- den. Additionally, this proposal is innovative and significant because it will (1) establish the processes and mechanisms through which parents’ and children’s neurophysiological regulation predicts treatment response, (2) clarify who might benefit from more intensive treatments, and (3) provide preliminary insight into potential treatment t...